1. Field of the Invention
The present invention relates to a circuit arrangement for controlling the level of electrical signals, and more particularly to a circuit wherein the signals are controlled to a constant level.
2. Description of the Prior Art
A circuit arrangement of this type is present, in principle, in conventional control amplifiers. The term `amplifier` is used generically and covers devices that can both increase and decrease current as required by the control. For the sake of simplicity, `amplifier` will be used in the following text instead of the term `circuit arrangement`.
The use of an amplifier in the transmission of analog and digital signals is unproblematic if a continuous signal transmission is present. An excessively high input signal can be processed, for example, by an overmodulation of the amplifier. Problems occur, however, in so-called `burst operation` in which signal bursts between large spaces are to be processed. A non-continuous signal transmission of this type is present, for example, in the bidirectional transmission of signals in a burst operation. Satisfactory processing of such signals is not possible with the amplifiers of the prior art. In the prior art, the signals are distorted, because the bandwidth and the dynamic range of the known amplifiers are not sufficient to convert the bursts arriving at large intervals into an output signal with a constant level. This defect of the known amplifiers can lead to the fact that no useful signal is available at the output. In that case, the signal transmission is not possible overall.